The biodynamic response of the seated human body has been investigated with 20 males exposed to upward and downward shocks at 13 fundamental frequencies (1-16 Hz) and 18 magnitudes (up to ±8.3 ms-2). For 1- and 2- degree-of-freedom models, the stiffness and damping coefficients were obtained by fitting seat acceleration waveforms predicted from the measured force to the measured seat accelerati...

This paper investigates simple implicit force control algorithms realizable with industrial robots. A lot of approaches already published are difficult to implement in commercial robot controllers, because the access to the robot joint torques is necessary or the complete dynamic model of the manipulator is used. In the past we already deal with explicit force control of a position controlled r...

In this work, ab initio parametrization of water force field is used to get insights into the functional form of empirical potentials to properly model the physics underlying dispersion interactions. We exploited the force matching algorithm to fit the interaction forces obtained with dispersion corrected density functional theory based molecular dynamics simulations. We found that the standard...

The mechanical instabilities and viscoelastic response of individual multiwalled carbon nanotubes and nanofibers (MWCNTs/Fs) under uniaxial compression are studied with atomic force microscopy. Specific buckling events are evident by regimes of negative stiffness, i.e., marked drops in force with increasing compression. Uniaxial cyclic loading can be repeatedly executed even in initially postbu...

Ambient operation poses a challenge to atomic force microscopy because in contrast to operation in vacuum or liquid environments, the cantilever dynamics change dramatically from oscillating in air to oscillating in a hydration layer when probing the sample. We demonstrate atomic resolution by imaging of the KBr(001) surface in ambient conditions by frequency-modulation atomic force microscopy ...

1.1 The force F acting on a dipole in an external field H, taken from [24]. 13 1.2 Magnetization torque (a)) without damping, the magnetization M pre-cesses around the H on a constant orbit. With damping (b)) the torque pointing towards H forces the magnetization to align with the external

The impact of damping effect and external forces to the DNA breathing is investigated within the Peyrard-Bishop model. In in the continuum limit, the dynamics of the breathing of DNA is described by the forced-damped nonlinear Schrodinger equation and studied by means of variational method. The analytical solutions are obtained for special cases. It is shown that the breather propagation is dec...

This paper presents the design of a computer-controlled pin-on-disk tribometer for friction characterization of various friction sliding pairs. The tribometer setup comprises two high-bandwidth servomotors for the control of the rotating disk and the normal load-related spindle drive, as well as a high-precision tri-axial piezoelectric force sensor for normal and tangential forces measurement. ...

Abstract. We derive a form for the non-conservative damping forces on metal ions due to their interactions with electrons, and present the result in the second-moment tight-binding approximation suitable for direct and efficient inclusion in a large-scale molecular dynamics simulation. We demonstrate that this form accurately captures the direction, velocity, temperature and local atomic enviro...

Yaw damper represents a major source of excitation for flexural vibration of the railway carbody. In order to reduce transmissibility of such undesired excitation, yaw damper should allow for large force transmission at low working frequencies, but should behave as vibration isolator at high working frequencies. Unfortunately, the yaw oil damper (OD), which is nowadays in service, has poor intr...